Physiological mechanisms of the receptor system

When we manipulate objects in our environment, a vast array of receptors in the skin, joints and muscles is activated. This information is relayed to the central nervous system and underlies two distinct but complementary aspects of hand function. Most obviously, these neural signals lead to haptic perception. We may sense how rough or smooth a surface is, or how curved an object is, whether it is soft or hard, whether the surface is slippery or sticky, how heavy it is and so on. Less obvious, but equally important, is the use the motor control system makes of these sensory signals in order to ensure appropriate hand movements resulting in stable grasps and effective complex manipulations. Some examples of common manipulations in our daily lives are: lifting a cup of coffee, opening a door, getting dressed, typing a manuscript, threading a needle.